As of at least build 7906, if a message comes in that fails SPF, even if it's from a trusted domain, it gets sent to junk anyway.  This has created multiple support calls that could have been avoided if, as a system admin, I had the option to change that setting at the domain level.  While I agree that DNS for all domains should have properly configured SPF records that explicitly authorize all applicable sending IPs, the fact is that some simply do not.  Perhaps a company changed or added vendors but forgot to update its DNS, who knows.  What I do know is that when my clients put a normal email address or domain into their Trusted Senders/Domains list, they fully expect it will no longer be sent to junk.  

Rather than hard coding this setting, please give SmarterMail system admins the ability to change it at the domain level.  This could save us a good bit of support time trying to explain why clients' Trusted Senders/Domains lists are not working as expected.